The TSA plans to field 120 canine teams at airports nationwide to sniff for explosives on passengers by the end of the year.

The TSA has tested canine teams in closed areas of airports in Miami last June and in Oklahoma City in August. Another test is scheduled in February at Washington’s Dulles airport. In recent months, TSA has experimented with screening passengers at airports in Tampa and Indianapolis.

But a Government Accountability Office (GAO) report released Thursday says that canine teams repeatedly fail to meet a requirement to get for four hours of training every four weeks. And GAO says that after short-notice tests of the teams, TSA doesn’t keep track of where dogs were most effective or with which types of explosives.

“TSA has not deployed passenger-screening canines — trained to identify and track explosives odor on a person — consistent with its risk-based approach, and did not determine (the canine) teams’ effectiveness prior to deployment,” the GAO concludes.

The TSA says that beyond its ongoing testing and evaluation, it will update its website that monitors the program in March to better track the passenger screening by dogs in the same way it does for cargo.

“TSA has developed a risk-based deployment methodology that it continues to evaluate and modify, as needed,” Jim Crumpacker, director of the agency’s liaison with GAO, wrote in reply to the report. “TSA will deploy future teams to the highest-priority airports as identified by both operational and risk-based analysis.”

The TSA effort is called the National Canine Program, which began in 1972 after a bomb threat on a plane. The program now has 762 teams of dogs and officers. The program is growing: Funding doubled to $101 million in the past three years, and there are plans for 921 teams.

Officers go through a 10- or 12-week training course at Lackland Air Force Base in Texas or at Auburn University’s Canine Detection Training Center in Alabama. The dogs include German shepherds, Belgian Malinoises, Vizslas and other types of dogs with good noses for the work.

Dogs began screening aviation cargo in January 2008, and there are now 120 TSA teams doing that. Hundreds of other dogs work with local law-enforcement officers patrolling airport, bus and ferry terminals. By the end of the year, TSA plans to have 120 teams of its inspectors paired with dogs to search for explosives on passengers in airports.

TSA Administrator John Pistole explained in a December presentation that the dogs are part of a program called “managed inclusion,” where passengers can qualify for expedited screening called Precheck if the dogs approve. On the day before Thanksgiving in Indianapolis, Pistole said 31% of the passengers were able to go through Precheck leaving on their shoes and jackets, and leaving laptops in their bags, rather than the typical 5%.

“We can make sure that TSA Precheck lanes are being fully utilized during the checkpoint hours because frankly most of them are not being fully utilized during the checkpoint hours,” Pistole said.

But the GAO says seven unnamed airport operators have declined dog-sniffing teams for passengers because of concerns about how they would deal with suicide bombers.

If TSA received a specific threat against an airport, the agency says it would deploy the teams despite the opposition. But in general, TSA is trying to work cooperatively with local authorities.

GAO also visited two “high-risk” airports with TSA canine teams used for cargo screening or training because TSA hadn’t reached an agreement with law-enforcement officers about how to respond if the dogs found a bomb.

TSA inspectors don’t carry weapons, although local law-enforcement officers do. An unidentified group of law-enforcement officers recommended that TSA dog teams be accompanied by law enforcement officers, GAO says.

The cost to TSA for a canine team with a law-enforcement handler is $53,000 and a TSA handler is $164,000, according to GAO.